Juan Cole shares health tips at his history blog

I am sure they are smart people, but every once in a while the journalists working for the mainstream media deliver themselves of the opinion that exercise does not help you lose weight, or that, indeed, there is no way to lose weight.

This article in Time says that the reporter's friends removed the benefit of the exercise they had done by going to Starbucks afterward and having a muffin. But he implies that they are doomed to do so. No blame is laid on corporate food for America's weight problems, even though that is among the main culprits.

Look, exercise and calories are not that complicated. If a man gets on a treadmill for a little over an hour at a brisk pace, he should be using 600 calories. If he also eats sensibly, and if he does the exercise at least five times a week, he should lose a pound a week. Regular exercise and eating sensibly should allow him to take off 4 pounds in a month. That may seem a pittance for someone who has put on a lot of weight, but it is 48 pounds a year, which should suffice for most people.

It is true that aerobic exercise causes you to lose muscle as well as fat, and such exercise should be combined with weight lifting to replace the lost muscle. Muscle tissue uses more calories than other kinds, and so having more of it also helps keep the weight off.

Of course, diet is also key. When you're trying to lose weight, you can't be eating muffins at Starbucks. You may crave them more, as the article asserts, if you exercise vigorously. But you aren't doomed to give in to the craving. And, there are other things that would satisfy the craving. A Starbucks blueberry muffin is on the order of 400 calories, and many of the drinks are 200 to 400. So obviously eating and drinking there carelessly would more than wipe out an hour's hard exercise. But instead, you could have a tall non-fat capuccino for 100 calories and a biscotti for 160, coming in at 240 total, and preserving 360 of the exercise savings. If you were hard core about losing weight, you could just have the coffee of the day or a cafe Americano, which have hardly any calories at all, and some fruit. Or you could stop at a soup and sandwich place instead of Starbucks, and have a cup of lentil soup for 200 calories; that dish is high in protein, which is what your body is really craving after hard exercise, not muffins.

What the Time article neglects to note is that how many calories you take in at Starbucks only matters in the context of your total intake for the day. If you eat a lighter than usual lunch, then the 240 calories picked up at Starbucks might not matter very much. Especially if you are exercising about an hour a day.

Most people aren't good at translating their pangs into wise choices because they haven't educated themselves about processed foods served them by corporations and restaurants. The body also plays tricks. Sometimes you feel hungry when you are really just thirsty, and drinking some water would be enough.

When you talk about avoiding too much fat, it sounds puritanical and as though we are stuck with celery and raw broccoli. But avoiding fat is mostly a matter of reading the labels of the things we buy in the grocery store. The main problem facing Americans in particular with regard to the obesity epidemic is that our processed food sold to us by our corporations is typically unhealthy. I had my gall bladder out a few years ago and before the operation was put on a nonfat or very low fat diet. I thought, well I'll make myself some spaghetti with tomato sauce. So I went to the grocery store and checked the spaghetti noodles, and they were loaded with fat. Then I checked the pre-made tomato sauce and it was floating in fat. Now, I don't think wheat and tomatoes have a lot of fat in them naturally. It is being added by the corporations, just as high fructose corn syrup is being added, because fat, sugar and salt make food addictive for consumers, and they want to sell us as much food as they can.

I personally think that the Atkins low-carb diet works for a lot of people mainly because it makes them avoid processed carbohydrates like cereal and pasta that have had fat and sugar poured into them at some factory. It would certainly make them avoid the Starbucks muffins and (worse) scones.

Exercise also has many health and cognitive benefits, including in fighting cancer and Alzheimer's, quite apart from the weight issue. And, most people don't realize that if you don't do resistance training such as working with weights, after age 45 your muscles will turn to jelly. I was outraged when I discovered this datum at age 47, because no health care provider had ever warned me about it. Luckily, the deterioration of the muscles can be reversed with weight training. Running or playing tennis won't help with this loss of muscle mass, it has to be doing curls. Otherwise, muscles deteriorate and fat increases, which is easy since muscle tissue uses more calories than other kinds, and you have less of it as you age unless you work out.

The science on all this is perfectly clear. Vigorous exercise (both aerobic and resistance training) combined with a low-fat diet is what allows people to take weight off and keep it off. Time is shockingly wrong.